Preparation of petroleum impregnating pitches from pyrolysis fuel oil using two‑step heat treatments

Jong‑Eun Choi,Seunghyun Ko,Young‑Pyo Jeon 한국탄소학회 2019 Carbon Letters Vol.29 No.4

Petroleum-based impregnating pitches were prepared from pyrolysis fuel oil (PFO) using a two-step heat treatment without a separation process. The pressurized heat treatment, the first step, was used to improve the properties of the pitches and enhance the product yield by promoting the cracking and polymerization of the components in the PFO. An atmospheric heat treatment as the second step was used only to synthesize the impregnating pitches from the liquid pitches prepared during the first step. The prepared impregnating pitches had the properties of a commercial petroleum-based impregnating pitch. The impregnation performance was evaluated by HT-XRD and an impregnation test. The HT-XRD results showed changes in the stacked structure of the pitches at the impregnation temperature. The bulk density of the carbon block was increased to 14.3% and the porosity was reduced by 10.3% after the impregnation/recarbonization process. The high reaction temperature during the first step induced the formation of quinoline insoluble (QI) components during the second step of the treatment, and the QI components adversely affected the impregnation process.

장애학생을 위한 검사 조정과 학업성취 수준 분석

최종근,김동일,김은주 국립특수교육원 2005 특수교육연구 Vol.12 No.1

본 연구는 장애학생들이 국가수준 학업성취도 평가에 본격적으로 참여하기에 앞서, 이들 장애학생들에게 요구되는 검사 조정 방안을 모색하고 이들의 기초학습 및 기본학습 능력 수준을 파악하기 위하여 이루어진 전국규모의 조사연구이다. 본 연구를 위해 일반학생 520명과 전국 29개 특수학교 중등부 3학년 학생(시각, 청각, 지체부자유) 144명의 성취수준과 부진학생 비율을 비교하였다. 분석 결과, 한국 장애학생의 기초학습 부진학생 비율은 일반학생의 3-5% 내외에 비해 훨씬 많은 30-50% 안팎에 이르고, 기본학습부진학생(보충학습 대상자) 비율도 일반학생의 10% 내외에 비해 훨씬 많은 60-70% 안팎에 이르는 것으로 나타났으며 특히 청각장애학생의 학업성취수준이 낮은 것으로 나타났다. 따라서 향후 정책적인 측면에서 장애학생들의 기초학습 기능 및 학업성취 수준을 향상시키기 위한 교육의 질 제고에 초점을 두어야 할 것이다. The purpose of this study was to compare the basic learning skill and academic achievement test score of students with disabilities(SWD) with those of general education students', and to identify the change of request for test modification or accommodations(TA) of SWD before and after the test. The participants of this study were 144 9th-grade SWD(the visually impaired, the hearing impaired, and the physically handicapped) from 29 special schools nation-wide, and 520 9th-grade general education students from a school from metropolitan area. In this study, SWD could choose any kind of TA among presentation, response, timing or scheduling, and setting/others. The results could be summarized as follows: (a) Compared to general 3-5%, 30-50% of SWD were categorized as defecting basic learning skill, and compared to general 10%, 60-70% of SWD were categorized as underachievers(in reading, writhing, and math). (b) SWD requested unexpectedly various test accommodations. (c) In order to attain the "appropriate" TA, a well-designed research on impacts of TA should be conducted in the future.

Bromobenzene에 유도된 간 독성에 미치는 Scoparone의 효과(Ⅱ)

최종원,김은주 慶星大學校 環境問題硏究所 1992 環境硏報 Vol.2 No.1

Brcmobenzene 투여로 야기되는 간독성의 경감에 scoparone 이 관여하는가를 간찰할 목적으로 간 조직중과산화 지질생성, 혈액증 생화확 검사 및 형채학적 측면에서 비교 관찰하여 다음과 같은 결과를 얻었다. 급성독성 시험에서 bromobenzene(1,000㎎/㎏)을 복강내에 주사하였을 때 사망률이 현저히 증가되던 것이 scoparone(5㎎/㎏)을 전처리함으로 대조군 수준으로 감소되었다. 간 조직증 과산화 지질함량도 bromobenzene(310㎎/㎏) 투여로 현저히 증가되던 것이scoparone, scopoletin 전처리로 억제되었으며, 혈청증 aminotransferase 와so-rbitol dehydrogenase 활성 변동에서도 지질과산화 생성과 유사한 결과이었다. 형채학적 검사에서bromobenzene의 투여로 간괴사, 세포의 파괴등의 변화가 scoparone, scopoletin 투여로 정상적인 세포가 형성되었으나, esculetin의 전처리로는 bromobenzene에 의한 간조직 병변의 변화에 아무런 영향을 미치지 않았다. Scoparone is derivatives of coumarin and the hydrogen of 6 and 7 position of coumarin moeity was substituted by methoxy groups. We have studied the mechanism by examing the protective effect of scoparone on the brom obenzene-induced hepatotoxicity. Scoparone poretreatment before the administration of bromobenzene has blocked subsequent increase in liver to body weight ratio. When biological changes were measured, scoparone and scopoletin protects against bromobenzene inducible hepatotoxicity in rats as evidenced by the decreased formation of lipid peroxide, lowered serum aminotransferase(ALT,AST) and sorbitol dehydrogenase(SDH) activties and reduced acute toxicity. It was also observed that histological changes of livers with scoparone and scopoletin pretreatment were less sever than in livers that was only bromobenzene-injected rats. Consquently, it was abserved that the mechanism for the observed protective effect of scoparone against the bromobenzene-induced hepatotoxicity by the scopoletin, the intermediate metabolite of scoparone.

HIV 감염/AIDS을 처음 진단받은 환자들의 특성과 임상에서 보편적인 HIV 검진의 가치

김종화,김태형,추은주,전민혁,서성우,이용관,최문한 순천향의학연구소 2008 Journal of Soonchunhyang Medical Science Vol.14 No.2

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만성 재발성 소아 흉통의 원인 질환과 임상양상

최은정,이은아,이창우,최두영,오연균,김종덕,윤향석 대한소아과학회 2004 小兒科 Vol.47 No.6

조기위암의 형태학적인 분류에 따른 임파절 전이 양상

최은서,강길,박정희,장정환,김권천,김경종,민영돈 朝鮮大學校 附設 醫學硏究所 2004 The Medical Journal of Chosun University Vol.29 No.1

Currently, in the limited cases of early gastric cancer (EGC), endoscopic mucosal resection (EMR) is used for curative treatment. However, its completeness is still controversial. The purpose of this study was to review the suggested indications of EMR. We retrospectively analyzed 234 patients with EGC who underwent curative (RO) gastrectomy. The enrolled cases were further classified into mucosal and submucosal types, and mucosal EGC were further classified according to the size, gross type and histologic pattern. 133 patients had mucosal cancers and 101 patients submucosal. The overall incidence of positive lymph node was 14.1% (33/234), the incidence of mucosal cancer was 8. 3% (11/133), which was significantly lower than that of submucosal, 22% (22/101). Of 133 patients with mucosal EGC, 90 were smaller than 2㎝ in size and the incidence of lymph node metastasis was 5.6% (5/90), compared to 43 of larger than 2㎝ with the incidence of 14% (6/43). According to the gross type classification of mucosal cancer, incidence of lymph node metastasis in protruded type (EGC type Ⅰ, Ⅱa, Ⅰ+Ⅱa) was 15.4% (4/26), nat type(EGC type Ⅱb) 2. 9% (1/35), depressed type (EGC type Ⅱc, Ⅲ) 8.3% (6/72). Lymph node metastasis in differentiated type of mucosal cancer was 6.9% (5/72) and undifferentiatcd type 9.8% (6/61). In this study, there was no single indication free from lymph node metastasis, It is thought that the selection of EMR for the curative treatment of EGC should be considered carefully and more clinical studies with long-term follow up are necessary for EMR to be generally acceptable.

디이젤기관의 흡입선회유동에 관한 연구

정동화,최은순,박상규 麗水水産大學校産業技術硏究所 1992 産業基術硏究所 論文集 Vol.1 No.-

Enhancement of performance of engine depends upon how perfectly combustion is effected, and air swirl is a factor contributing to this aim. In this paper, the variation of induction air swirl according to intake port shapes is studied by steady flow test. As a result of the steady flow test, using various shapes of intake port the following points are clarified. 1. Air swirl in actual engine cylinder can be fully estimated by steady flow test. 2. A valve position can have a substantial effect upon swirl. 3. The change of port inlet area has an effect on the variation of air swirl.

개의 아토피 피부염에 대한 Leflunomide의 임상적 적용 1례

홍은지,윤기영,서경원,최호정,정성목,송근호,조종기,박성준 忠南大學校 獸醫科大學 附設 動物醫科學硏究所 2012 動物醫科學硏究誌 Vol.19 No.1

A Shih-tzu(8-year-old, castrated male) was referred to the Veterinary Medical Teaching Hospital of Chungnam National University with the history of relapsing pruritus, recurrent dermatitis. On the physical examination, generalized erythema, otitis externa, alopecia and lichenification were observed. Using Favrot's criteria for diagnishing atopic dermatitis, 7 criteria were satisfied out of 8 criteria. After treatment for infection, intradermal skin test was performed(positive allergen : Df, Dp). And then immunotherapy was performed, but clinical signs were not getting better. Next treatment of glucocorticoid shown little improvement of clinical signs, and adverse effect(diarrhea) was shown after cyclosporine application. So application of leflunomide which is used for human atopic dermatitis treatment in some case was planned. After 6 months of application of leflunomide, clinical signs were decreased gradually.

수평 매복된 상악 견치의 교정적 견인

최형준,이종은,이제호,이종갑 大韓小兒齒科學會 2003 大韓小兒齒科學會誌 Vol.30 No.4

치아 매복은 구강점막이나 악골내에서 치아의 맹출이 중지된 상태를 의미하며, 제 3구대구치와 상악 견치에서 호발한다. 상악 견치의 매복은 주로 측절치가 상실되거나 왜소한 경우와 연관성이 높지만 치배의 위치 이상과 같이 유전적인 요소와도 관련될 수 있다. 매복치는 심미적, 기능적으로 여러 가지 문제점을 야기하므로 조기에 진단하여 치료하는 것이 중요하며, 매복치의 상태에 따라서 치료 방법을 적절하게 선택하여야 한다. 본 증례는 11세 여아에서 구개측으로 수평 매복된 상악 우측 견치의 치료를 보고한 것으로, 매복치는 외과적 수술을 동반한 교정적 견인 방법을 사용하여 기능적, 심미적으로 회복되었다. 견인 치료는 매복 견치의 맹출 공간을 확보하면서 이루어졌으며, 치료 종료 후 매복 견치는 치근 흡수와 같은 합병증 없이 적절한 부착치은을 확보하여 양호하게 위치되었다. Tooth impaction is defined as a cessation of the eruption of a tooth at the level of the oral mucosa or alveolar bone. Maxillary canines are the most frequently impacted teeth next to the third molar. Maxillary canine impaction is associated with congenital missing of lateral incisors, peg lateralis and genetic factors such as ectopic positioning of a tooth germ. The clinicians have an important role in early detectionof tooth impaction for prevention of esthetic and functional problems. There are specific methods to treat impacted tooth for different conditions. In this case, an 11-year-old girl with a horizontally impacted maxillary right canine in a palatal position was treated through orthodontic traction along with surgical button attachment procedure. On regaining of eruption space, canine traction was performed. At the completion of treatment, the canine was positioned fairly within the arch with proper keratinized gingiva and complications such as root resorption were not observed.

항만하역 근로자들의 직업적 특성과 사회심리적 스트레스에 관한 연구

최은경,이종태,손혜숙,이성훈 인제대학교 백병원 2002 仁濟醫學 Vol.23 No.5

Objective : The objective of this study is to evaluate the job characteristics of container terminal workers by applying the Job Strain model, and to assess the relationship among the general characteristics, job characteristics and psychosocial distress. Methods and Material : A self-administrated questionnaire survey was performed in Busan. The subjects were consisted of 100 white-collar workers and 100 blue-collar workers. We used Karaseks Job Content Questionnaire for evaluation of the job characteristics and Psychosocial well-being index (PWI) for measuring the extent of their psychosocial stress. Results : In white-collar workers, the skill discretion, created skill, decision-making authority, decision-making latitude, psychological job demand, and supervisor support of the job characteristics were significantly high, while in blue-collar workers physicalexertion was significantly high. PWl reveals that blue-collar workers were mere stressed than white-collar workers, especially, the factor 2, 3 and 4 were significantly increased; whereas, in white-collar workers, only the index of factor 1 was significantly increased. And PWl scores were significantly increased in the lower social support and psychological job demand. blue-collar workers had increased odds ratio of 2.66(95% CI:1.11-6.41) compared with white-collar workers. The unmarried workers increased odds ratio of 3.54(95% CI;1.18-10.62) compared with married workers. And workers who have not own house increased odds ratio of 2.35(95% CI;1.15-4.79) compared with workers who have own house. Particularly, odds ratio of work-shift in blue-collar workers was 11.10(2.14-57.64). (multiple logistic regression analysis PWI). Conclusion : The results of this study correspond with the fact that The more job demand is high and Job control is low, the more job stress is high. Job stress of blue-collar workers was comparatively higher than that of white-collar workers, sleeping, smoking, and work shifting turned out to be a main cause that increases stress. Therefore, in order to decrease the job stress, a health promotion program to change the health behaviors should be activated and an organized job stress management program should be introduced. Especially, working condition for blue-collar such as physical exertion and work-shift should be improved.